spreadsheet problem
 

I have entered inventory numbers into a column i.e. B:1 thru B:20, I want to
enter a number in a remote cell i.e H:1 to subtract a value from cells B1
thru B:20.

The B:1 thru B:20 cellls will be added to daily, the H:1 cell will be used
to releve these cells of inventory from assembled product.

The H:1 cell entry must not change cells B:1 thru B:20 except with the
current numerical entry.

I really appreciate the assist and hope I was clear on my intent.